One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(9,10,15,14)(11,16,12,17)(13,18,22,21)(19,23,20,24)(25,26)(27,28)(29,33)(30,32)(31,34)(35,36)(37,39)(38,40)(1,3,5,8)(2,6,4,7)(9,11,15,12)(10,16,14,17)(13,19,22,20)(18,23,21,24)(25,27)(26,31)(28,32)(29,35)(30,34)(33,38)(36,39)(37,40)(1,4,5,2)(3,7,8,6)(10,14)(16,17)(18,21)(23,24)(26,32)(27,34)(29,37)(36,38)(9,12,15,11)(10,17,14,16)(13,19,22,20)(18,23,21,24)(25,28,30,31)(26,27,32,34)(29,38,37,36)(33,40,39,35)(9,13)(10,18)(11,19)(12,20)(14,21)(15,22)(16,23)(17,24)(25,27)(26,31)(28,32)(29,35)(30,34)(33,38)(36,39)(37,40) involution — undirected(9,14,15,10)(11,17,12,16)(13,21,22,18)(19,24,20,23)(25,29,30,37)(26,33,32,39)(27,35,34,40)(28,36,31,38)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.